Display substrate comprising fingerprint recognition sensors, method for manufacturing the same, and display device

ABSTRACT

Embodiments of the present disclosure relate to a display substrate, a method for manufacturing the same, and a display device. The display substrate includes a substrate, a pixel definition layer for defining pixels on the substrate, the pixel definition layer including a plurality of inter-pixel portions located between adjacent pixels, and a fingerprint recognition sensor located in the inter-pixel portions.

CROSS REFERENCE TO RELATED APPLICATIONS

This patent application is a National Stage Entry of PCT/CN2018/117167filed on Nov. 23, 2018, the disclosure of which is incorporated byreference herein in its entirety as part of the present application.

BACKGROUND

Embodiments of the present disclosure relate to the field of displaytechnology, and in particular, to a display substrate, a method formanufacturing the same, and a display device.

Since fingerprints have characteristics of invariance, uniqueness andconvenience, they have almost become synonymous with biometricidentification. Fingerprint refers to ridge lines produced by unevennesson a front skin of an end of a human finger. The ridge lines areregularly arranged to form different patterns. A starting point, anending point, a joining point, and a bifurcation point of the ridgelines are called as minutiae. Fingerprint recognition refers toidentification performed by comparing the minutiae of differentfingerprints. Fingerprint recognition technology involves manydisciplines such as image processing, pattern recognition, computervision, mathematical morphology, wavelet analysis, etc. As thefingerprints are different among persons and even fingerprints of tenfingers of one person are significantly different, the fingerprints canbe used for identity authentication and can replace traditionalpasswords to achieve higher and more secure secrecy. Therefore, thedisplay devices having fingerprint recognition function have becomeincreasingly popular.

BRIEF DESCRIPTION

Embodiments of the present disclosure provide a display substrate and amethod for manufacturing the same.

One aspect of the present disclosure provides a display substrate. Thedisplay substrate includes a substrate, a pixel definition layer fordefining pixels on the substrate, the pixel definition layer including aplurality of inter-pixel portions located between adjacent pixels, and afingerprint recognition sensor located in at least one of theinter-pixel portions.

In an embodiment of the present disclosure, the fingerprint recognitionsensor is an ultrasonic fingerprint recognition sensor, and theultrasonic fingerprint recognition sensor includes a generator and areceiver.

In an embodiment of the present disclosure, the generator and thereceiver are located in different inter-pixel portions, respectively.

In an embodiment of the present disclosure, the generator and thereceiver are located in a same inter-pixel portion.

In an embodiment of the present disclosure, the generator includes afirst lower electrode, a first piezoelectric material, and a first upperelectrode which are sequentially stacked in a direction away from thesubstrate. In an embodiment of the present disclosure, the receiverincludes a second lower electrode, a second piezoelectric material, anda second upper electrode which are sequentially stacked in a directionaway from the substrate.

In an embodiment of the present disclosure, the first lower electrode isdisposed in the same layer as the second lower electrode, and the firstupper electrode is disposed in the same layer as the second upperelectrode.

In an embodiment of the present disclosure, the first piezoelectricmaterial is disposed in the same layer as the second piezoelectricmaterial.

In an embodiment of the present disclosure, a cross-sectional shape ofthe generator and the receiver parallel to a surface of the substrateincludes a square, a circle, a triangle, or a rhombus.

In an embodiment of the present disclosure, the pixel includes a lightemitting device. The light emitting device includes an anode, a lightemitting layer, and a cathode which are sequentially disposed in adirection perpendicular to the substrate. The anode is disposed in thesame layer as the first lower electrode and the second lower electrode.The cathode covers the pixel definition layer and the light emittinglayer.

In an embodiment of the present disclosure, the display substratefurther includes a TFT layer located between the substrate and the lightemitting device and located between the substrate and the pixeldefinition layer, a planarization layer located between the TFT layerand the light emitting device and located between the TFT layer and thepixel definition layer, an encapsulation layer located on the cathode,and a touch layer located on the encapsulation layer.

One aspect of the present disclosure provides a display device includinga display substrate as described above.

One aspect of the present disclosure provides a method for manufacturinga display substrate. The method includes providing a substrate, forminga pixel definition layer for defining pixels on the substrate, andforming the pixels on the substrate and in the pixel definition layer.The pixel definition layer includes a plurality of inter-pixel portionslocated between adjacent pixels. In an embodiment of the presentdisclosure, forming the pixel definition layer includes forming afingerprint recognition sensor in at least one of the inter-pixelportions.

In an embodiment of the present disclosure, the fingerprint recognitionsensor is an ultrasonic fingerprint recognition sensor, and theultrasonic fingerprint recognition sensor includes a generator and areceiver. Forming the ultrasonic fingerprint recognition sensor includespositioning the generator and the receiver in different inter-pixelportions or positioning the generator and the receiver in a sameinter-pixel portion.

In an embodiment of the present disclosure, forming the ultrasonicfingerprint recognition sensor includes positioning the generator andthe receiver in different inter-pixel portions. The inter-pixel portionincludes a first inter-pixel portion and a second inter-pixel portion.In an embodiment of the present disclosure, forming the firstinter-pixel portion, the second inter-pixel portion, and the ultrasonicfingerprint recognition sensor includes forming a first lower electrodein a region for forming the first inter-pixel portion on the substrate,and forming a second lower electrode in a region for forming the secondinter-pixel portion on the substrate, forming a first portion of thefirst inter-pixel portion covering the substrate and the first lowerelectrode in the region for forming the first inter-pixel portion, andforming a first portion of the second inter-pixel portion covering thesubstrate and the second lower electrode in the region for forming thesecond inter-pixel portion, forming a first hole exposing the firstlower electrode in the first portion of the first inter-pixel portion,and forming a second hole exposing the second lower electrode in thefirst portion of the second inter-pixel portion, forming a firstpiezoelectric material in the first hole, and forming a secondpiezoelectric material in the second hole, forming a first upperelectrode on the first portion of the first inter-pixel portion and thefirst piezoelectric material, and forming a second upper electrode onthe first portion of the second inter-pixel portion and the secondpiezoelectric material, and forming a second portion of the firstinter-pixel portion on the first upper electrode and the first portionof the first inter-pixel portion, and forming a second portion of thesecond inter-pixel portion on the second upper electrode and the firstportion of the second inter-pixel portion.

In an embodiment of the present disclosure, forming the first lowerelectrode and the second lower electrode includes forming a firstconductive layer on the substrate, and patterning the first conductivelayer to form the first lower electrode in the region for forming thefirst inter-pixel portion and form the second lower electrode in theregion for forming the second inter-pixel portion. In an embodiment ofthe present disclosure, forming the first upper electrode and the secondupper electrode includes forming a second conductive layer covering thefirst portion of the first inter-pixel portion and the firstpiezoelectric material and covering the first portion of the secondinter-pixel portion and the second piezoelectric material, andpatterning the second conductive layer to form the first upper electrodeon the first portion of the first inter-pixel portion and the firstpiezoelectric material and form the second upper electrode on the firstportion of the second inter-pixel portion and the second piezoelectricmaterial.

In an embodiment of the present disclosure, forming the ultrasonicfingerprint recognition sensor includes positioning the generator andthe receiver in the same inter-pixel portion. Forming the ultrasonicfingerprint recognition sensor includes forming a first lower electrodeand a second lower electrode in a region for forming the inter-pixelportion on the substrate, forming a first portion of the inter-pixelportion covering the substrate, the first lower electrode, and thesecond lower electrode in the region for forming the inter-pixelportion, forming a first hole exposing the first lower electrode and asecond hole exposing the second lower electrode in the first portion ofthe inter-pixel portion, forming a first piezoelectric material in thefirst hole, and forming a second piezoelectric material in the secondhole, forming a first upper electrode on the first portion of theinter-pixel portion and the first piezoelectric material, and forming asecond upper electrode on the first portion of the inter-pixel portionand the second piezoelectric material, and forming a second portion ofthe inter-pixel portion on the first portion of the inter-pixel portion,the first upper electrode, and the second upper electrode.

In an embodiment of the present disclosure, forming the first lowerelectrode and the second lower electrode includes forming a firstconductive layer on the substrate, and patterning the first conductivelayer to form the first lower electrode and the second lower electrodein the region for forming the inter-pixel portion. In an embodiment ofthe present disclosure, forming the first upper electrode and the secondupper electrode includes forming a second conductive layer covering thefirst portion of the inter-pixel portion, the first piezoelectricmaterial and the second piezoelectric material, and patterning thesecond conductive layer to form the first upper electrode on the firstportion of the inter-pixel portion and the first piezoelectric materialand form the second upper electrode on the first portion of theinter-pixel portion and the second piezoelectric material.

In an embodiment of the present disclosure, the pixel includes a lightemitting device. Forming the light emitting device includes forming ananode on the substrate, wherein the anode is formed simultaneously withthe first lower electrode and the second lower electrode, forming thelight emitting layer on the anode, and forming a cathode on the lightemitting layer and the pixel definition layer.

In an embodiment of the present disclosure, the method further includesforming a TFT layer on the substrate before forming the pixel definitionlayer and the fingerprint recognition sensor, and forming aplanarization layer on the TFT layer, forming an encapsulation layer onthe cathode after forming the cathode, and forming a touch layer on theencapsulation layer.

Adaptive and further aspects and scope will become apparent from thedescription provided herein. It should be understood that variousaspects of this disclosure may be implemented individually or incombination with one or more other aspects. It should also be understoodthat the description and specific examples herein are intended forpurposes of illustration only and are not intended to limit the scope ofthe present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings described herein are for illustrative purposes only ofselected embodiments and not all possible implementations, and are notintended to limit the scope of the present application.

FIG. 1 is a schematic diagram showing a positional relationship betweena display substrate and a fingerprint recognition sensor;

FIG. 2 is a schematic diagram showing a positional relationship betweena display substrate and a fingerprint recognition sensor according to anembodiment of the present disclosure;

FIG. 3 is a schematic plan view of a display substrate according to anembodiment of the present disclosure;

FIG. 4 is a schematic cross-sectional view of a display substrateaccording to an embodiment of the present disclosure;

FIG. 5 is a schematic plan view of a display substrate according to anembodiment of the present disclosure;

FIG. 6 is a schematic cross-sectional view of a display substrateaccording to an embodiment of the present disclosure;

FIG. 7 is a flowchart of a method for manufacturing a display substrateaccording to an embodiment of the present disclosure; and

FIGS. 8A to 17B are schematic plan and cross-sectional views of a methodfor manufacturing a display substrate according to an embodiment of thepresent disclosure.

Corresponding reference numerals indicate corresponding parts orfeatures throughout the several views of the drawings.

DETAILED DESCRIPTION

As used herein and in the appended claims, the singular form of a wordincludes the plural, and vice versa, unless the context clearly dictatesotherwise. Thus, the references “a”, “an”, and “the” are generallyinclusive of the plurals of the respective terms. Similarly, the words“comprise”, “comprises”, and “comprising” are to be interpretedinclusively rather than exclusively. Likewise, the terms “include”,“including” and “or” should all be construed to be inclusive, unlesssuch a construction is clearly prohibited from the context. The term“example” used herein, particularly when followed by a listing of terms,is merely exemplary and illustrative and should not be deemed to beexclusive or comprehensive.

Additionally, further to be noted, when the elements and the embodimentsthereof of the present application are introduced, the articles “a/an”,“one”, “the” and “said” are intended to represent the existence of oneor more elements. Unless otherwise specified, “a plurality of” means twoor more. The expressions “comprise”, “include”, “contain” and “have” areintended as inclusive and mean that there may be other elements besidesthose listed. The terms such as “first” and “second” are used hereinonly for purposes of description and are not intended to indicate orimply relative importance and the order of formation.

In addition, in the drawings, the thickness of each layer and the regionwhere each layer positioned are exaggerated for clarity. It should beunderstood that when referring to a layer, a region, or a componentbeing located “on” another part, it means that the layer, the region orthe component is directly located on another part, or there may be othercomponents located between the layer, the region or the component andanother part. In contrast, when a component is referred to as being“directly” located on another component, it means that no othercomponent is located between them.

The flowchart depicted in present disclosure is only an example. Theremay be many variations to this flowchart or the steps described thereinwithout departing from the spirit of the present disclosure. Forexample, the depicted steps may be performed in a different order, orsteps may be added, deleted, or modified. These variations areconsidered as part of the claimed aspect.

Exemplary embodiments will now be described more fully with reference tothe accompanying drawings.

Currently, there are three main technologies for fingerprint recognitionapplied to smart phones: capacitive, optical, and ultrasonictechnologies. At present, the most mature fingerprint mobile phones onthe market are basically capacitive. However, with the launch offull-screen phones, the location of the capacitive sensor needs to bedesigned to avoid occupying the area of the body of the mobile phone. Inaddition, because the optical and ultrasonic sensors can be directlyattached to the lower part of back of the display, and thus no morerestrictions will be applied to the appearance of the mobile phone,major mobile phone manufacturers and scientific research institutionsactively carry out technical research on it.

Ultrasonic fingerprint recognition technology refers to performfingerprint recognition by employing ultrasonic waves to scanfingerprint. Compared with capacitive touch screen fingerprinttechnology, ultrasonic fingerprint technology has many unique advantagesincluding the ability to scan through a smartphone case made of glass,stainless steel, sapphire, or plastic and overcome the problem thatfingerprints cannot unlock mobile phone due to sweat, oil, and dirt,thereby providing a more stable and accurate authentication method. Inaddition, ultrasonic waves can penetrate directly through the skinsurface, so as to recognize three-dimensional details and uniquefingerprint features including fingerprint ridges and sweat pores thatcannot be recognized by current capacitive touch screen basedfingerprint technology. Thus, fingerprint surface maps which are rich indetail and difficult to imitate can be generated. However, the currentultrasonic fingerprint recognition module needs to be attached to thelower part of back of the display, which will increase cost includingmodule equipment, labor, time, etc. Therefore, while developing theultrasonic fingerprint recognition technology, it is also necessary todevelop the manufacturing process for mass production about thetechnology.

FIG. 1 is a schematic diagram of a positional relationship between adisplay substrate and a fingerprint recognition sensor. As shown in FIG.1, the fingerprint recognition sensor 200 is located outside the displaysubstrate 100, that is, the fingerprint recognition sensor 200 isattached to the outside of the display substrate 100. Such structurerequires additional fitting equipment, and thus increased costs aboutlabor, time, etc.

FIG. 2 is a schematic diagram of a positional relationship between adisplay substrate and a fingerprint recognition sensor according to anembodiment of the present disclosure. As shown in FIG. 2, thefingerprint recognition sensor 200 is integrated within the displaysubstrate 100, which can reduce the process of attaching the fingerprintrecognition sensor to the display substrate, thereby improvingproductivity, simplifying manufacturing processes, and saving costs.

FIG. 3 is a schematic plan view of a display substrate according to anembodiment of the present disclosure. FIG. 4 is a schematiccross-sectional view of a display substrate taken along a line AAaccording to an embodiment of the present disclosure. FIG. 5 is aschematic plan view of a display substrate according to an embodiment ofthe present disclosure. FIG. 6 is a schematic cross-sectional view of adisplay substrate taken along a line AA according to an embodiment ofthe present disclosure. It should be noted that the fingerprintrecognition region shown in FIG. 3 and FIG. 5 is located within thedisplay region of the display substrate 100. However, the position ofthe fingerprint recognition region shown in FIG. 3 and FIG. 5 is onlyexemplary and should not be considered as a limitation to the presentdisclosure, and those skilled in the art may choose position of thefingerprint recognition region according to actual needs.

In an embodiment of the present disclosure, as shown in FIGS. 4 and 6,the display substrate 100 includes a substrate 101, a pixel definitionlayer 105 for defining pixels 104 on the substrate 101, wherein thepixel definition layer 105 includes a plurality of inter-pixel portions105 located between adjacent pixels 104, and a fingerprint recognitionsensor located in the inter-pixel portion 105. The pixel definitionlayer can be formed, for example, as a mesh structure with multipleopenings. The inter-pixel portion can be, for example, a solid portionbetween openings. The opening is used to form a pixel. One inter-pixelportion can be, for example, an integral of the solid part between twoadjacent pixels. The pixel definition layer can be formed, for example,as an accommodating space surrounded by dams. The accommodating spacecan be used to form pixels, for example. The inter-pixel portion can bethe dam structure. One inter-pixel portion can be, for example, anintegral of the dam structure between two pixels. The pixel may include,for example, a light emitting device. Since the fingerprint recognitionsensor is integrated in the pixel definition layer, it does not affectthe display of the display substrate. In addition, it should be notedthat, in the display region of the display substrate, the thickness ofthe inter-pixel portion provided with the fingerprint recognition sensorand the thickness of the inter-pixel portion provided without thefingerprint recognition sensor may be the same, so as to not affect thesubsequent structure.

In an embodiment of the present disclosure, the fingerprint recognitionsensor is an ultrasonic fingerprint recognition sensor. In an embodimentof the present disclosure, as shown in FIGS. 4 and 6, the ultrasonicfingerprint recognition sensor includes a generator 210 and a receiver220.

On one hand, in an embodiment of the present disclosure, as shown inFIGS. 3 and 4, the generator 210 and the receiver 220 are located indifferent inter-pixel portions 105, respectively. The differentinter-pixel portions may be, for example, inter-pixel portions ondifferent sides of the same pixel. The different inter-pixel portionsmay be, for example, inter-pixel portions on the same side of differentpixels. On the other hand, in an embodiment of the present disclosure,as shown in FIGS. 5 and 6, the generator 210 and the receiver 220 mayalso be located in the same inter-pixel portion 105. The sameinter-pixel portion may be, for example, an inter-pixel portion betweentwo adjacent pixels. For example, the two adjacent pixels may be in anarrangement direction of the two adjacent pixels. There are no otherpixels between the two adjacent pixels. For example, two adjacent pixelsand the inter-pixel portion may be an integral and there is no openingbetween the two adjacent pixels. The generator and the receiver may, forexample, be arranged along the arrangement direction of the two adjacentpixels, or may be arranged along a direction perpendicular to thearrangement direction of the two adjacent pixels.

Specifically, as shown in FIGS. 4 and 6, the generator 210 includes afirst lower electrode 211, a first piezoelectric material 212, and afirst upper electrode 213 which are sequentially stacked in a directionaway from the substrate 101. The receiver 220 includes a second lowerelectrode 221, a second piezoelectric material 222, and a second upperelectrode 223 which are sequentially stacked in a direction away fromthe substrate 101.

In an embodiment of the present disclosure, the first lower electrode211 is disposed in the same layer as the second lower electrode 221, andthe first upper electrode 213 is disposed in the same layer as thesecond upper electrode 223. Here, the “being disposed in the same layer”means that they are formed of the same material layer.

In an embodiment of the present disclosure, the first piezoelectricmaterial 212 is disposed in the same layer as the second piezoelectricmaterial 222. It should be noted that the first piezoelectric material212 and the second piezoelectric material 222 may also be formed ofdifferent piezoelectric materials, and those skilled in the art maychoose the piezoelectric material according to actual needs.

In an embodiment of the present disclosure, the first piezoelectricmaterial 212 and the second piezoelectric material 222 may include anorganic material, an inorganic material, a semiconductor material, or acombination thereof.

In an exemplary embodiment of the present disclosure, the organicmaterial may include polyvinylidene fluoride (Ethene, 1,1-difluoro-,homopolymer, or PVDF), polyvinyl fluoride (PVF), or polyvinyl chloride(PVC).

In an exemplary embodiment of the present disclosure, the inorganicmaterial may include quartz or piezoelectric ceramic.

In an exemplary embodiment of the present disclosure, the semiconductormaterial may include ZnS, CdTe, or GaAs.

As an example, the first piezoelectric material 212 and the secondpiezoelectric material 222 can be obtained by dissolving polyvinylidenefluoride in N, N-dimethylformamide (DMF) or N-methyl pyrrolidone (NMP)to form a solution, followed by processes including coating thesolution, baking, annealing, etc.

As another example, the first piezoelectric material 212 and the secondpiezoelectric material 222 may be a composite piezoelectric materialincluding polyvinylidene fluoride and lead zirconate titanatepiezoelectric ceramic transducer (PZT), so as to obtain more excellentpiezoelectric performance.

In an embodiment of the present disclosure, the cross-sectional shape ofthe generator 210 and the receiver 220 parallel to the surface of thesubstrate 101 include a square, a circle, a triangle, or a rhombus.

In an embodiment of the present disclosure, as shown in FIGS. 4 and 6,the pixel 104 includes a light emitting device 104. The light emittingdevice 104 includes an anode 1041, a light emitting layer 1042, and acathode 1043 which are sequentially disposed in a directionperpendicular to the substrate 101. The cathode 1043 covers the pixeldefinition layer 105 and the light emitting layer 1042.

In an embodiment of the present disclosure, the anode 1041 is disposedin the same layer as the first lower electrode 211 and the second lowerelectrode 221.

In an embodiment of the present disclosure, as shown in FIGS. 4 and 6,the display substrate 100 further includes a TFT layer 102 locatedbetween the substrate 101 and the light emitting device 104 and locatedbetween the substrate 101 and the pixel definition layer 105, aplanarization layer 103 located between the TFT layer 102 and the lightemitting device 104 and located between the TFT layer 102 and the pixeldefinition layer 105, an encapsulation layer 106 located on the cathode1043, and a touch layer 107 located on the encapsulation layer 106. Itshould be noted that, in the case where the light emitting layer 1042emits white light, the touch layer 107 further includes a color filmlayer, so that the display substrate 100 can implement color display.

In an exemplary embodiment of the present disclosure, the light emittingdevice 104 may be an OLED light emitting device or a QLED light emittingdevice.

In an exemplary embodiment of the present disclosure, the TFT layer 102may include a low temperature poly-silicon (LTPS) layer, an indiumgallium zinc oxide (IGZO) layer, or an a-Si layer.

In an embodiment of the present disclosure, the substrate 101 may be aflexible substrate or a rigid substrate. In an exemplary embodiment ofthe present disclosure, the rigid substrate may include glass, plastic,or metal.

In an embodiment of the present disclosure, a display device is alsoprovided. The display device includes the display substrate as describedabove.

In an embodiment of the present disclosure, a method for manufacturing adisplay substrate is also provided. The display substrate manufacturedby this method is shown in FIGS. 4 and 6.

FIG. 7 is a flowchart of a method for manufacturing a display substrateaccording to an embodiment of the present disclosure. As shown in FIG.7, the method includes steps S701 to S703. In step S701, a substrate isprovided; in step S702, a pixel definition layer for defining pixels isformed on the substrate; and in step S703, pixels are formed on thesubstrate and in the pixel definition layer. In an embodiment of thepresent disclosure, the pixel definition layer includes a plurality ofinter-pixel portions located between adjacent pixels.

In an embodiment of the present disclosure, forming a pixel definitionlayer includes forming a fingerprint recognition sensor in theinter-pixel portion.

In an embodiment of the present disclosure, the fingerprint recognitionsensor is an ultrasonic fingerprint recognition sensor. The ultrasonicfingerprint recognition sensor includes a generator and a receiver.

In one aspect, in an embodiment of the present disclosure, forming anultrasonic fingerprint recognition sensor includes positioning thegenerator and the receiver in different inter-pixel portions. In thisembodiment, the manufactured display substrate is shown in FIG. 4.

Next, a method for forming the inter-pixel portion and the ultrasonicfingerprint recognition sensor so as to position the generator and thereceiver in different inter-pixel portions will be described in detailwith reference to FIGS. 8A to 12B.

In an embodiment of the present disclosure, the inter-pixel portion mayinclude a first inter-pixel portion 1051 and a second inter-pixelportion 1052.

FIG. 8A is a schematic plan view of a method for manufacturing a displaysubstrate according to an embodiment of the present disclosure. FIG. 8Bis a schematic cross-sectional view taken along the line AA in FIG. 8A.

As shown in FIGS. 8A and 8B, a first lower electrode 211 is formed in aregion 105 a for forming the first inter-pixel portion on a substrate101, and a second lower electrode 221 is formed in a region 105 b forforming the second inter-pixel portion on the substrate 101.

Specifically, forming the first lower electrode 211 and the second lowerelectrode 221 includes forming a first conductive layer (not shown) onthe substrate 101, and patterning the first conductive layer to form thefirst lower electrode 211 in the region 105 a for forming the firstinter-pixel portion and form the second lower electrode 221 in theregion 105 b for forming the second inter-pixel portion.

It should be noted that, as shown in FIG. 8A, wirings and pad a for thefirst lower electrode 211 and the second lower electrode 221 are alsoformed in the bonding region of the substrate 101 at the same time asthe first lower electrode 211 and the second lower electrode 221 areformed. In addition, in an embodiment of the present disclosure, pads bfor the first upper electrode 213 and the second upper electrode 223 (tobe described later) corresponding to the first lower electrode 211 andthe second lower electrode 221 are formed at the same time as the pads aare formed. It should be noted that the design of the wiring in thebonding region of the present disclosure is only exemplary and shouldnot be considered as a limit to the present disclosure, and thoseskilled in the art may design it according to actual needs.

In an embodiment of the present disclosure, the bonding region is usedfor bonding a corresponding flexible printed circuit (FPC) board or achip on film (COF). Specifically, the pads a and b in the bonding regionare used to bond the corresponding FPC and COF. The pads a and b may begenerally referred to “gold fingers”.

FIG. 9A is a schematic plan view of a method for manufacturing a displaysubstrate according to an embodiment of the present disclosure. FIG. 9Bis a schematic cross-sectional view taken along the line AA in FIG. 9A.

As shown in FIGS. 9A and 9B, a first portion 1051 a of the firstinter-pixel portion covering the substrate 101 and the first lowerelectrode 211 is formed in the region 105 a for forming the firstinter-pixel portion, and a first portion 1052 a of the secondinter-pixel portion covering the substrate 101 and the second lowerelectrode 221 is formed in the region 105 b for forming the secondinter-pixel portion. A first hole 1051 a′ exposing the first lowerelectrode 211 is formed in the first portion 1051 a of the firstinter-pixel portion, and a second hole 1052 a′ exposing the second lowerelectrode 221 is formed in the first portion 1052 a of the secondinter-pixel portion.

In an embodiment of the present disclosure, the first hole 1051 a′ andthe second hole 1052 a′ may be formed using a patterning processincluding exposure, development, etc.

In an embodiment of the present disclosure, the first portion 1051 a ofthe first inter-pixel portion and the first portion 1052 a of the secondinter-pixel portion also cover the wiring in the bonding region, therebyavoiding being connected to subsequently formed wiring for the firstupper electrode 213 and the second upper electrodes 223 (to be describedlater).

FIG. 10A is a schematic plan view of a method for manufacturing adisplay substrate according to an embodiment of the present disclosure.FIG. 10B is a schematic cross-sectional view taken along the line AA inFIG. 10A.

As shown in FIGS. 10A and 10B, a first piezoelectric material 212 isformed in the first hole 1051 a′, and a second piezoelectric material222 is formed in the second hole 1052 a′.

It should be noted that, for specific materials of the firstpiezoelectric material 212 and the second piezoelectric material 222,reference may be made to the above descriptions of FIGS. 4 and 6, anddetails are not described herein again.

As an example, the first piezoelectric material 212 and the secondpiezoelectric material 222 can be prepared by dissolving polyvinylidenefluoride in N, N-dimethylformamide or N-methylpyrrolidone to obtain asolution, coating the first hole 1051 a′ and the second hole 1052 a′with this solution, annealing the structure thus obtained in an ovenunder the temperature of 30-80° C., thereby obtaining the firstpiezoelectric material 212 and the second piezoelectric material 222.

As another example, a lead zirconate titanate piezoelectric ceramictransducer may be added to the above solution, and other steps are thesame as those in the above example, thereby obtaining the firstpiezoelectric material 212 and the second piezoelectric material 222having a composite piezoelectric material, so as to achieve moreexcellent piezoelectric performance.

FIG. 11A is a schematic plan view of a method for manufacturing adisplay substrate according to an embodiment of the present disclosure.FIG. 11B is a schematic cross-sectional view taken along the line AA inFIG. 11A.

As shown in FIGS. 11A and 11B, a first upper electrode 213 is formed onthe first portion 1051 a of the first inter-pixel portion and the firstpiezoelectric material 212, and a second upper electrode 223 is formedon the first portion 1052 a of the second inter-pixel portion and thesecond piezoelectric material 222.

Specifically, forming the first upper electrode 213 and the second upperelectrode 223 includes forming a second conductive layer (not shown)covering the first portion 1051 a of the first inter-pixel portion andthe first piezoelectric material 212 and covering the first portion 1052a of the second inter-pixel portion and the second piezoelectricmaterial 222, and patterning the second conductive layer to form thefirst upper electrode 213 on the first portion 1051 a of the firstinter-pixel portion and the first piezoelectric material 212 and formthe second upper electrode 223 on the first portion 1052 a of the secondinter-pixel portion and the second piezoelectric material 222.

In an embodiment of the present disclosure, the first lower electrode211, the first piezoelectric material 212, and the first upper electrode213 constitute the generator 210 of the ultrasonic fingerprintrecognition sensor. The second lower electrode 221, the secondpiezoelectric material 222, and the second upper electrode 223constitute the receiver 220 of the ultrasonic fingerprint recognitionsensor.

In an embodiment of the present disclosure, the first lower electrode211, the second lower electrode 221, the first upper electrode 213, andthe second upper electrode 223 may be prepared through processes such assputtering, exposure, and etching, etc.

It should be noted that, as shown in FIG. 11A, wiring for the firstupper electrode 213 and the second upper electrode 223 are also formedin the bonding region of the substrate 101 while the first upperelectrode 213 and the second upper electrode 223 are formed. It shouldbe noted that the design of wiring in the bonding region of the presentdisclosure is only exemplary and should not be considered as a limit tothe present disclosure, and those skilled in the art may design itaccording to actual needs.

FIG. 12A is a schematic plan view of a method for manufacturing adisplay substrate according to an embodiment of the present disclosure.FIG. 12B is a schematic cross-sectional view taken along the line AA inFIG. 12A.

As shown in FIGS. 12A and 12B, a second portion 1051 b of the firstinter-pixel portion is formed on the first upper electrode 213 and thefirst portion 1051 a of the first inter-pixel portion, and a secondportion 1052 b of the second inter-pixel portion is formed on the secondupper electrode 223 and the first portion 1052 a of the secondinter-pixel portion.

In an embodiment of the present disclosure, the second portion 1051 b ofthe first inter-pixel portion and the second portion 1052 b of thesecond inter-pixel portion also cover the wiring in the bonding region.

On the other hand, in an embodiment of the present disclosure, formingthe ultrasonic fingerprint recognition sensor includes positioning thegenerator and the receiver in the same inter-pixel portion. In thisembodiment, the manufactured display substrate is shown in FIG. 6.

Next, a method for forming the inter-pixel portion and the ultrasonicfingerprint recognition sensor so as to position the generator and thereceiver in the same inter-pixel portion will be described in detailwith reference to FIGS. 13A to 17B.

FIG. 13A is a schematic plan view of a method for manufacturing adisplay substrate according to an embodiment of the present disclosure.FIG. 13B is a schematic cross-sectional view taken along line AA in FIG.13A.

As shown in FIGS. 13A and 13B, a first lower electrode 211 and a secondlower electrode 221 are formed in a region 105′ for forming theinter-pixel portion on a substrate 101.

Specifically, forming the first lower electrode 211 and the second lowerelectrode 221 includes forming a first conductive layer (not shown) onthe substrate 101, and patterning the first conductive layer to form thefirst lower electrode 211 and the second lower electrode 221 in theregion 105′ for forming the inter-pixel portion.

It should be noted that, as shown in FIG. 13A, wirings and pad a for thefirst lower electrode 211 and the second lower electrode 221 are alsoformed in the bonding region of the substrate 101 at the same time asthe first lower electrode 211 and the second lower electrode 221 areformed. In addition, in an embodiment of the present disclosure, pads bfor the first upper electrode 213 and the second upper electrode 223 (tobe described later) corresponding to the first lower electrode 211 andthe second lower electrode 221 are formed at the same time as the pads aare formed. It should be noted that the design of the wiring in thebonding region of the present disclosure is only exemplary and shouldnot be considered as a limit to the present disclosure, and thoseskilled in the art may design it according to actual needs.

In an embodiment of the present disclosure, the bonding region is usedfor bonding a corresponding flexible printed circuit board or a chip onfilm.

FIG. 14A is a schematic plan view of a method for manufacturing adisplay substrate according to an embodiment of the present disclosure.FIG. 14B is a schematic cross-sectional view taken along the line AA inFIG. 14A.

As shown in FIGS. 14A and 14B, a first portion 105 c of the inter-pixelportion covering the substrate 101, the first lower electrode 211 andthe second lower electrode 221 is formed in the region 105′ for formingthe inter-pixel portion. A first hole 105 c′ exposing the first lowerelectrode 211 and a second hole 105 c″ exposing the second lowerelectrode 221 are formed in the first portion 105 c of the inter-pixelportion.

In an embodiment of the present disclosure, the first hole 105 c′ andthe second hole 105 c″ may be formed using processes such as exposure,development, etc.

In an embodiment of the present disclosure, the first portion 105 c ofthe inter-pixel portion also covers the wiring in the bonding region,thereby avoiding being connected to subsequently formed wiring for thefirst upper electrode 213 and the second upper electrodes 223 (to bedescribed later).

FIG. 15A is a schematic plan view of a method for manufacturing adisplay substrate according to an embodiment of the present disclosure.FIG. 15B is a schematic cross-sectional view taken along the line AA inFIG. 15A.

As shown in FIGS. 15A and 15B, a first piezoelectric material 212 isformed in the first hole 105 c′, and a second piezoelectric material 222is formed in the second hole 105 c″.

For the detailed description of the first piezoelectric material 212 andthe second piezoelectric material 222, reference may be made to theabove descriptions of FIGS. 4 and 6 above, and details are not describedherein again.

FIG. 16A is a schematic plan view of a method for manufacturing adisplay substrate according to an embodiment of the present disclosure.FIG. 16B is a schematic cross-sectional view taken along the line AA inFIG. 16A.

As shown in FIGS. 16A and 16B, a first upper electrode 213 is formed onthe first portion 105 c of the inter-pixel portion and the firstpiezoelectric material 212, and a second upper electrode 223 is formedon first portion 105 c of the inter-pixel portion and the secondpiezoelectric material 222.

Specifically, forming the first upper electrode 213 and the second upperelectrode 223 includes forming a second conductive layer (not shown)covering the first portion 105 c of the inter-pixel portion, the firstconductive material 212 and the second conductive material 222, andpatterning the second conductive layer to form the first upper electrode213 on the first portion 105 c of the inter-pixel portion and the firstpiezoelectric material 212 and form the second upper electrode 223 onthe first portion 105 c of the inter-pixel portion and the secondpiezoelectric material 222.

In an embodiment of the present disclosure, the first lower electrode211, the first piezoelectric material 212, and the first upper electrode213 constitute the generator 210 of the ultrasonic fingerprintrecognition sensor. The second lower electrode 221, the secondpiezoelectric material 222, and the second upper electrode 223constitute the receiver 220 of the ultrasonic fingerprint recognitionsensor.

In an embodiment of the present disclosure, the first lower electrode211, the second lower electrode 221, the first upper electrode 213, andthe second upper electrode 223 may be prepared through processes such assputtering, exposure, and etching, etc.

It should be noted that, as shown in FIG. 16A, wiring for the firstupper electrode 213 and the second upper electrode 223 are formed in thebonding region of the substrate 101 at the same time as the first upperelectrode 213 and the second upper electrode 223 are formed. It shouldbe noted that the design of the wiring in the bonding region of thepresent disclosure is only exemplary and should not be considered as alimit to the present disclosure, and those skilled in the art may designit according to actual needs.

FIG. 17A is a schematic plan view of a method for manufacturing adisplay substrate according to an embodiment of the present disclosure.FIG. 17B is a schematic cross-sectional view taken along the line AA inFIG. 17A.

As shown in FIGS. 17A and 17B, a second portion 105 d of the inter-pixelportion is formed on the first portion 105 c of the inter-pixel portion,the first upper electrode 213, and the second upper electrode 223.

In an embodiment of the present disclosure, the second portion 105 d ofthe inter-pixel portion also covers the wiring in the bonding region.

Further, referring to FIGS. 4 and 6, forming the light emitting device104 includes forming an anode 1041 on the substrate 101, forming a lightemitting layer 1042 on the anode 1041, and forming a cathode 1043 on thelight emitting layer 1042 and the pixel definition layer 105. Inaddition, in an embodiment of the present disclosure, the anode 1041 ofthe light emitting device 104 is disposed in the same layer as the firstlower electrode 211 and the second lower electrode 221, and thus may beformed at the same time.

Furthermore, in an embodiment of the present disclosure, referring toFIGS. 4 and 6, the method for manufacturing a display substrate furtherincludes before forming the pixel definition layer 105 and thefingerprint recognition sensor, forming a TFT layer 102 on the substrate101, and forming a planarization layer 103 on the TFT layer 102. Inaddition, after forming the cathode 1043, an encapsulation layer 106 isformed on the cathode 1043, and a touch layer 107 is formed on theencapsulation layer 106.

It should be noted that, in the case where the light emitting layer 1042emits white light, the touch layer 107 further includes a color filmlayer, so that the display substrate 100 can implement color display.

For detailed descriptions of the substrate 101 and the TFT layer 102,reference may be made to the above description of FIG. 4 and FIG. 6, anddetails are not described herein again.

The foregoing description of the embodiment has been provided forpurpose of illustration and description. It is not intended to beexhaustive or to limit the application. Even if not specifically shownor described, individual elements or features of a particular embodimentare generally not limited to that particular embodiment, areinterchangeable when under a suitable condition, can be used in aselected embodiment and may also be varied in many ways. Such variationsare not to be regarded as a departure from the application, and all suchmodifications are included within the scope of the application.

What is claimed is:
 1. A method for manufacturing a display substratecomprising: providing a substrate; forming a pixel definition layer fordefining pixels on the substrate, wherein each pixel comprises a lightemitting device; and forming the light emitting devices on the substrateand in the pixel definition layer, the pixel definition layer comprisinga plurality of inter-pixel portions located between adjacent lightemitting devices, wherein forming the pixel definition layer comprisesforming a fingerprint recognition sensor in at least one of theinter-pixel portions, and wherein the fingerprint recognition sensor isan ultrasonic fingerprint recognition sensor, wherein the ultrasonicfingerprint recognition sensor comprises a generator and a receiver,wherein forming the ultrasonic fingerprint recognition sensor comprisespositioning the generator and the receiver in different inter-pixelportions, the inter-pixel portion comprising a first inter-pixel portionand a second inter-pixel portion located on opposite sides of eachpixel, and wherein forming the first inter-pixel portion, the secondinter-pixel portion, and the ultrasonic fingerprint recognition sensorcomprises: forming a first lower electrode in a region for forming thefirst inter-pixel portion on the substrate, and forming a second lowerelectrode in a region for forming the second inter-pixel portion on thesubstrate; forming a first portion of the first inter-pixel portioncovering the substrate and the first lower electrode in the region forforming the first inter-pixel portion, and forming a first portion ofthe second inter-pixel portion covering the substrate and the secondlower electrode in the region for forming the second inter-pixelportion; forming a first hole exposing the first lower electrode in thefirst portion of the first inter-pixel portion, and forming a secondhole exposing the second lower electrode in the first portion of thesecond inter-pixel portion; forming a first piezoelectric material inthe first hole, and forming a second piezoelectric material in thesecond hole; forming a first upper electrode on the first portion of thefirst inter-pixel portion and the first piezoelectric material, andforming a second upper electrode on the first portion of the secondinter-pixel portion and the second piezoelectric material; and forming asecond portion of the first inter-pixel portion on the first upperelectrode and the first portion of the first inter-pixel portion, andforming a second portion of the second inter-pixel portion on the secondupper electrode and the first portion of the second inter-pixel portion.2. The method according to claim 1, wherein forming the first lowerelectrode and the second lower electrode comprises: forming a firstconductive layer on the substrate; and patterning the first conductivelayer to form the first lower electrode in the region for forming thefirst inter-pixel portion and to form the second lower electrode in theregion for forming the second inter-pixel portion, and wherein formingthe first upper electrode and the second upper electrode comprises:forming a second conductive layer covering the first portion of thefirst inter-pixel portion and the first piezoelectric material andcovering the first portion of the second inter-pixel portion and thesecond piezoelectric material; and patterning the second conductivelayer to form the first upper electrode on the first portion of thefirst inter-pixel portion and the first piezoelectric material and toform the second upper electrode on the first portion of the secondinter-pixel portion and the second piezoelectric material.
 3. The methodaccording to claim 2, wherein forming each light emitting devicecomprises: forming an anode on the substrate, wherein the anode isformed simultaneously with the first lower electrode and the secondlower electrode; forming a light emitting layer on the anode; andforming a cathode on the light emitting layer and the pixel definitionlayer.
 4. The method according to claim 3, further comprising: forming aTFT layer on the substrate before forming the pixel definition layer andthe fingerprint recognition sensor; forming a planarization layer on theTFT layer; forming an encapsulation layer on the cathode after formingthe cathode; and forming a touch layer on the encapsulation layer.